


Unrestrained, Undone

by BrushDog



Category: DRAMAtical Murder - All Media Types
Genre: Cunnilingus, F/F, Face-Sitting, Incest, Orgasm Delay/Denial, Partial Mind Control, Plot What Plot/Porn Without Plot, Sexswap, Vaginal Fingering
Language: English
Status: Completed
Published: 2015-06-06
Updated: 2015-06-06
Packaged: 2018-04-03 03:18:35
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,425
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4084657
Author URL: https://archiveofourown.org/users/BrushDog/pseuds/BrushDog
Summary: <blockquote class="userstuff">
              <p>Desire's got a great idea, she just needs Sei to play along...</p>
            </blockquote>





	Unrestrained, Undone

**Author's Note:**

> I needed a break from my longer pieces so I challenged myself to write some shameless smut and this is what happened.
> 
> Kudos to Harukami for beta'ing.

"Hey, big sis. I've got a great idea."

The sudden declaration, made in a sultry purr against the shell of Sei's ear, doesn't come to her as too much of a surprise.

She's settled in on the floor of Aoba's room--the room she shares with Ren now--resting against Aoba's chest with a book open on her lap. The book is something that Ren was reading, but it was a long day for Ren with lots of chores and things to do. When she started to nod off, Sei politely asked to switch places to allow herself some time with her younger sister. Ren, of course, had willingly acquiesced.

It's been months now since she took the risk of allowing Ren to notice that fragments of her mind still survived in the body she had given over. Over that time, she's found that her mind has recovered more and more, that she's able to come to the surface more and more, and that she's able to share in Ren and Aoba's love more and more.

Of course, the situation isn't unique to her alone.

Aoba's hand, which had been resting easily against her hip as her younger sister paged idly through a magazine on the floor, is now sliding against the outside of her thigh, past the hem of her shorts and against bare skin. It's easy enough to tell that this isn't 'Aoba,' but rather the 'other Aoba,' Aoba's Desire, that resides in her mind much the same way that Sei resides within Ren's.

To Sei, they're both her precious sisters, two parts of the same woman she loves, so she doesn't mind it at all.

Carefully marking the place in Ren's book, she closes it and sets it aside, leaning more fully into Desire's embrace.

"What's that?" she asks, settling her hand down against Desire's, fingernails tracing lightly against the skin of her wrist.

"It feels like whenever I see you, you've got something on your mind, something you're worried about," Desire murmurs into the skin of Sei's neck, her free hand slipping under the hem of her shirt to stroke across her stomach.

"Does it seem like that?" Sei stretches her neck against Desire's lips, offering.

She doesn't mean to avoid her sister's question, but it's true that even though being with Ren has allowed her to see more of the world than she ever had the chance to see before, there's still damage in her heart. She tires easily. She doesn't always know the right thing to say, how to approach a situation without twisting her words for fear that her own desires won't be accepted, that her will has no power. She knows there's no need to worry about such things here, not with Ren or Aoba or Desire. Yet recovering from a lifetime of suffering isn't a simple feat. She simply doesn't want to burden her sisters with it.

"I wouldn't say it if it didn't," Desire says. Her nails are skirting lightly against the stretch marks on Sei's thighs now, the evidence of her body's shift to accommodate Ren's taller form. Sei shudders under the touch. "You were the first one to look out for me after we forgot everything. That's why I've gotta look out for you too."

Sei turns her head, just slightly, enough to drop a kiss to the corner of Desire's lips. "That's very kind of you," she says quietly, catching the bright flash of Desire's gaze with her own dark eyes.

Desire grins. "I always want to be kind to my precious big sister. That's why I was thinking...Sei. Why don't I use my power on you?"

"Your power...?" Sei blinks, confused. It's true that Aoba had used her power once, to destroy Sei, to free her from her body, but Desire can't be thinking of doing that sort of thing again, not after how far they've come.

"Yeah, the power of my voice." Desire's expression sombers, her grin falling away as her eyes focus intently on Sei's. Her hands stop their motions as well, pressing into Sei's skin instead, holding her close. "You'd asked us to use it before, to destroy you. But you know that's not all that it can do. There are parts of you that make you afraid, that make you hesitate. What if..." Desire pauses, her lips drawn tight, eyes narrowed slightly as they meet Sei's gaze "What if I destroyed those parts of you as well?"

Sei can feel a strange sort of nervous energy running through her body at the thought. She knows that Desire must feel it in her too. It's a strange thought. She's spent most of her life tearing away at parts of her mind. She gave birth to fragmented consciousnesses, pieces of herself, all so she could escape the hardship and pain of the world around her. In that way, she had spent most of her life slowly destroying herself.

Although being with Aoba and Ren is different, although she's found a way to exist and live, in a certain sense she knows that she can still feel the restraints of the cages she's spent her life living in. She's lived by doing as she's told, following orders and commands, both things said and unsaid. She found her own ways around it all, of course. She broke herself to squeeze into tiny openings where she could feel something like freedom, but it wasn't quite the same.

If Desire breaks those barriers, destroys the ghosts of cages and restraints that Sei feels around herself, would she be able to face it? Would she know what to do with that sort of freedom?

Almost as if she senses Sei's distress, Desire shifts behind her, nudging Sei to face her with a hand at her hip, gathering her up in a tight embrace as Sei follows the motion.

"We both know what it's like to be trapped," Desire says into Sei's hair, nuzzling with her words. "We both know what it's like to be caged. To feel like our words won't change a thing, like we can't breathe, like we can't move. But we're free now, Sei."

Sei lets out a slow breath, tilting her head up to look at Desire, dark eyes searching her expression. Desire meets her gaze with a slight grin, leaning in to steal a kiss that's surprisingly chaste, at least coming from her. 

Sei smiles in return, reaching up to cup Desire's cheek in her hand. "The two of us are free now," she repeats, returning Desire's kiss with one of her own.

"Yeah," Desire says, lips curling against Sei's. "There's no cage for you here, sis. There's no reason to be afraid. We can do whatever we want." 

Her hands slide down Sei's back, dipping under the hem of her shorts, fingers kneading into the fabric of her panties over her ass. Sei lets out a breathless laugh in reply, rolling her hips into the motion ever so slightly.

"All right," Sei says, sitting back on Desire's lap to meet her gaze properly. "Why don't you show me your power?"

Desire blinks, her eyes widening for a moment as though she wasn't expecting Sei to agree at all. But the surprise flickers away quickly, replaced by a wide grin, the white of her teeth peeking out from under curled lips. 

"All right," she says, her eyes flashing bright yellow, her words thick with power as they penetrate deep into Sei's mind. "Stand up. Strip for me."

The sensation of it is only slightly familiar for Sei. She feels something within her change at Desire's words, like a weight cast off her shoulders, like a barrier torn down. With smooth motions, she pulls herself from Desire's hold and stands, shoulders drawn back as she looks down to her younger sister with an easy smile against her lips. 

Ren had bathed earlier, so she isn't wearing much, only a tank top and some pajama shorts over her panties. Her hands find the hem of her tank top and pull it up, hips swaying with the motion. She can feel Desire's gaze on her, watching as the skin of her belly and breasts are exposed before she casts the garment away. 

Sei's never been particularly ashamed of the state of her body, but rather she feels an acute awareness of how it could be seen as flawed. Her joints are peppered with small, round scars from the countless injections and needles that were part of her experimentation. Across her arms, legs, stomach and breasts, faint stretch marks stand out against her pale skin from the changes her body went to accomodate Ren's larger form. Yet with Desire's command, Desire's power working within her mind, there's no hesitation in her movements as she pushes her shorts and panties down in one motion, lightly stepping out of them to stand before her sister, completely naked.

Desire seems to sense the change in her. Her face is flushed and grin wide when her eyes slowly track over every curve of Sei's body until she meets her sister's waiting gaze. Desire shifts against the side of the bed, pushing herself up to sit on its edge, holding one hand out to beckon to Sei, her eyes flashing again.

"Come here, Sei."

Sei steps forward, placing her legs to either side of Desire's knees as she does. Standing like this, Desire's eyes are nearly even with her breasts, but her sister's gaze doesn't stray from her face. Her hands, however, are hardly so patient. As soon as Sei is near enough, they reach out, palms sliding against the skin of Sei's thighs again, following their curve up, over her hipbones, until they rest at her waist. Sei shifts, letting out a pleased sigh at the warmth of Desire's touch, her own hands settling against Desire's wrists.

"What next?" she asks, playful, lowering her eyelids slightly as she gazes down at Desire.

"Why don't you stay right there for me," Desire says, hands finding Sei's ass as she squeezes again, "While I spoil you a little, sister."

Her lips are at Sei's breast before Sei has a chance to reply, kissing at Sei's skin with loud smacks and nips, quickly tracing a wet path to her nipple. Sei lets out a laugh under her breath as she nods, her hands drawing along the skin of Desire's arms.

"If that's what you'd like," she says, breathless, pressing her chest forward to the waiting attention of Desire's lips and teeth.

Desire only hums in reply against her skin, which makes Sei shudder. Her lips pull at Sei's nipple before her tongue lavishes over it in a wide swath, drawing a short gasp from Sei's lips as she can feel heat building in the flush of her cheeks and deep in her belly. Desire's hands are still on her, stroking against skin, but straying away from the heat between her legs. Instead, Desire drags her nails against the back of Sei's thighs, cupping behind her knees and drawing her forward until Sei tumbles rather unceremoniously onto the bed, straddling Desire's lap with her knees.

With a gasp, Desire pulls her lips away from Sei's breast, shifting back to accommodate Sei with a wild grin.

"This's a pretty good position to be in, isn't it sis?"

"You seem to be enjoying it." Sei smiles, coy, her heart racing at the sultry sound of her own voice.

"Looks like I'm not the only one," Desire says, her hands at the small of Sei's back as she meets her sister's gaze again, eyes flashing bright, voice resonating. "Why don't you tell me what you want, Sei?"

Sei shivers, her entirely body loosening as the heat coursing through her seems to burn hotter, the breath that was caught in her throat dissipating into nothing. She cups Desire's face between her palms, leaning in over her, her breath hot against her sister's lips.

"I want you to kiss me," she says, low and eager, before claiming those lips as her own.

They've kissed before, countless times, but all of them seem to fade away in comparison to this. Rather than her usual hesitance, her usual willingness to let Desire have what she wants of the kiss, this time Sei is the one to take the lead. Her fingers drag back against her sister's scalp, tangling in bright blue hair and pulling her in closer as their tongues twist together, their lips slipping against each other. She can feel the gasp that the motion pulls from Desire. She savors it, drinks it in until it melts into an eager moan, Desire's hands finding Sei's shoulderblades and pressing in, drawing Sei closer until the two of them tumble back against the bed, their lips never parting.

They kiss again and again. Sei feels a heady pleasure build inside her as she tastes Desire's lips, feels the slide of her sister's skin against her as Desire shifts beneath her, sliding a knee up between her legs. Sei grinds down against it willingly, feeling the wet smear it leaves over Desire's skin with a lustful pride. By the time she pulls away, gasping, a breathless laugh bubbles up from her chest, unrestrained and wanting. Beneath her, Desire echoes the laughter with an eager grin.

"You see what I mean?" she purrs, hands sliding up to cup Sei's breasts, squeezing them as her thumbs flick against the hardened nubs of her nipples. Sei moans, eager, arching into the touch. "You don't have to hold back from what you want, sis. I can give you anything, everything. All you need to do is ask and it's yours."

"That would be rather greedy of me, wouldn't it?" Sei asks through her haze of need, but at that moment, the familiar question sounds strange to her. Why would it be greedy to take what she wants?

"It's not greedy," Desire answers, helping to push the thought from Sei's mind. Her eyes flash again, half-lidded with her pupils blown wide. "Take what you want, Sei."

"I will," Sei says without hesitation, the breath pushed from her lungs with the force of her words. Greedily, she curves down over Desire again, taking her lips again as her hands seek to make quick work of her sister's clothes.

Desire, of course, is more than eager to help. Twisting and writhing under Sei with her eager moans of appreciation, it isn't long at all before they're lying naked together, skin to skin, hands moving against every bit of exposed flesh.

Sei's reluctant to tear her lips from Desire's, but as her hands find her sister's breasts, fingers rolling and pulling at her nipples, the loud and laughing moans that Desire gives her makes it seem worthwhile. She leans back, sitting against Desire's thighs, looking down at her sister's body spread before her, her hips and chest twisting with every touch, her blue hair tossed against the pillow as her mouth hangs open with her deep and pleading moans spilling from it.

It's intoxicating. It's wonderful. In this moment, Sei can't imagine how she's never realized that she could want anything but this.

"You're beautiful, Aoba," she says, smiling softly as she trails one hand down along the quivering line of Desire's stomach, fingers tracing lightly over the wet curls between her legs.

Desire looks up at her with a flushed grin, her hands resting against Sei's knees where they press into the mattress. "Of course I am," she says, panting. "I'm the one you want, aren't I?"

"Mhm," Sei nods, running a fingertip against Desire's folds, eyes drinking in the shiver it sends through the other girl's spine. She wonders at how easy it is to agree to something as simple as that now, how much power she can find in something as little as her own desires.

"I love you," she says, slipping her finger between Desire's folds, her smile widening at the eager gasp from her sister's lips. "I want you," she says as she traces a circle against her entrance, feeling the bite of Desire's nails as the grip on her thighs tightens. "So I can have you, can't I?"

"Yeah," Desire says, hasty, her hips rolling against Sei's finger, trying to push her deeper. When Sei pulls away there's a plaintive whine that spills from her lips her head tossing against the pillow with a rough laugh. "Come on, sis, you can take all of me, all right?"

"I can." Sei pauses for a moment, pulling her wet finger up to her lips, deliberately meeting Desire's gaze as the tip of her tongue peeks out, lapping against it. Desire moans out a curse, her body shaking under Sei's hold. Sei laughs. "But it's nice to savor things sometimes, isn't it?"

"Fucking hell, sis," Desire hisses between teeth clenched into a grin. "Never would've pegged you for a tease."

"Don't worry," Sei chides her, slipping her hand back between Desire's legs, fingertips tracing against her folds and clit. "I want to take care of you, Aoba. I want to let you feel what you've shown me."

"Shit--shit yes, sis--Sei!" Desire moans. Her hands grasp at the pillow beneath her head, back arching and hips rolling into the motion of Sei's fingers. Beneath her moans, reverberating somewhere even deeper inside her, Sei feels the thrumming power of Desire's voice once again. "Show it to me. Show me everything you want to do."

Her reservations gone, her fears banished, Sei is all too willing to give Desire exactly what she's asked for. She slips back on the bed, her fingers still stroking against Desire, keeping pace and pressure with the growing urgency in the rhythm of her hips. But Sei has other things in mind. She pulls her hands away at the last minute, shuddering at the sweet, pleading pitch of the whine that it pulls from Desire's throat before she plants her lips over her sister's clit, sucking and teasing against it with her teeth.

From the cry that Desire makes, Sei almost wonders if she's come just from that, but she knows it can't be true. She can still feel the walls of Desire's entrance quivering against her lower lip, wetness seeping from them with every twitch and roll of her hips. Sei's tasted it before. She can't think of a single part of her sister's body that she hasn't had the taste of by now, but this is different. There's no voice of doubt or hesitation at the back of her mind, no shadows of unnaturally bright eyes and wide grins from her past. When Desire grabs her hair and pulls, urging her deeper, faster, it doesn't send pain spider webbing across her skin but leaves her shuddering with pleasure instead, nails biting into the skin of her sister's thighs, her own moans trembling from her lips into the heat of Desire's sex.

Desire comes with a howling cry, back arched, heels digging into the bedsheets below. The force of it leaves Sei breathless. She has to pull away, lips wet and face flushed with her own pleasure, eyes half-lidded and dark as she watches the tension slip from Desire's body before her until she spreads bonelessly against the bed with a lewd moan.

"Sei...sister..." Desire says, voice low, fingers stroking languidly through her sister's dark hair. "That was amazing."

"I'm glad that you enjoyed it," Sei says, leaning into the touch, her senses returning to her like a feeling of pinpricks against her skin. Each one lights a fire, leaving her flushed and all too aware of the heat between her own legs. With her newfound confidence, she rises from where she's crouched against the bed, finding Desire's hands with her own and stroking against them, along the length of her arms as she rises over the other woman's body.

"But you know, it isn't over yet."

Desire meets her eyes, one eyebrow quirked, before a lazy grin spreads over her face. Her hands find Sei's hips, drawing them up and forward.

"There's still something else you want, isn't there?"

"There is," Sei nods, reaching up to brace herself on the headboard, knees planting against the pillows to either side of Desire's head. Desire strokes against her thighs, from the tops of her knees and inward, all the way up, teasing at the wet heat between Sei's legs. It brings a laugh to Sei's lips, fond and light.

"But I think this time, I'd like to return your favor."

"Return it?"

"That's right." Sei smiles down at her, feeling the swell of her own power building in her throat, sparking behind her eyes like flashes of light. "Aoba. Show me what you want?"

Desire's eyes widen, her breath caught with the jolt as Sei's powers course through her. Her recovery is swift, lips curling as her hands reach up to pull at Sei's hips, dragging her down.

"Gladly," she purrs before sinking her teeth into the soft skin of Sei's thigh, drawing it into her mouth, sucking against it hard enough to mark.

Sei moans, rich and deep. Her head tosses back, her fingers curling against the headboard, shuddering with the bite of Desire's teeth, the soft wet pass of her lips. She rolls her hips down, shifting them, trying to urge her sister's mouth just ever so slightly to where she wants it the most when she feels Desire's fingers catch her legs in a tight grip.

Startled, Sei looks down, a plaintive whine slipping from her lips as she does, her cheeks flushing at how needy the sound is.

Desire's eyes meet hers, curved with the smile that Sei feels against the skin of her thigh. She pulls away with a loud smack, flashing teeth up to Sei as she does.

"You're not the only one who's a tease, sis," Desire says, a purr low in her throat as she turns, her nose just barely brushing against the edge of Sei's folds before her lips find the skin of her thigh, drawing it in, marking it in a mirror image of the other side.

Sei pants, struggling to find her words as her breath pulls from her in a floating laugh. "So you want to give me... what I gave you?" she asks, twisting her hips against Desire's grip just to feel the press of her fingertips against skin.

"That's right," Desire says, pulling away again, seemingly pleased with the marks she's left. "I want to tease you. I want to make you beg until I've heard every pretty moan that you can make. I want to build you up until you shout my name so loud even Granny can hear it."

Sei laughs again, the sound melting into a moan as Desire's tongue traces along the edge of her folds, lazily drinking up the moisture gathered there.

"Granny's--not home tonight," she pants, eyes half-lidded as she looks down to her sister, "You know that."

"That's true," Desire says, nipping at Sei's folds, letting her teeth slide against the wet skin before they click together in a wide grin. "You'll just have to make sure you scream loud enough for her to hear."

"Ah," Sei gasps, her entire body shuddering with the sensation. "Is that so--"

"That's what it is."

True to her word, Desire is merciless. Her lips, tongue, and teeth seem to be absolutely everywhere against Sei's skin. They nibble against her thigh at one moment and trace along her entrance the next. The sucking heat of Desire's mouth against her clit draws an eager moan from her lips only for it to dissolve into a needy whine as she's left bereft, hips struggling and shuddering against Desire's hold as she tries to seek out more. It seems that every time the heat in her builds, every time she can feel her walls start to tense and pulse with the flood of her orgasm, Desire is gone, resting against the pillows with a pleased smirk on her lips, eyes taking in Sei's body as her breasts shaking over heaving breaths, as her mouth hangs open, eyes a dark and deep black as she desperately pleads for more.

Sei's usual gasps and half-moans are long forgotten now. Her throat aches with the force of every sound that Desire draws from it, but she can't stop them, she won't stop them now. She wants Desire to see this, wants to show her sister, her lover, just how much pleasure her touch brings, just how much she wants this.

She loses track of how many times Desire brings her to the edge only to pull back again. Her entire body is shuddering, her head bowed, arms shaking with the effort of holding to the headboard, of keeping herself upright.

"Sei," she hears Desire purr from between her legs.

She opens her eyes, half-lidded, and swallows before she finds her words again.

"Aoba."

"That's right," Desire says. "Say my name."

"Aoba," she gasps, and Desire's lips find her clit again, sucking as she brushes her tongue over it in quick strokes.

"Aoba," she moans when Desire's hand finally releases her hip, cutting a short line across her belly to plunge two fingers deep inside her.

"Aoba--!" she cries out, back arched, head tossed back, as she finally feels release crashing over her, sparks behind her eyes as her body tenses with the heat of the pleasure coursing through her veins.

She's barely aware of her body slipping down to the bed, hands sliding from the headboard to rest limply at her sides. She feels Desire's arms curl around her and she turn into them, burrowing lazily into the warmth of her sister's chest, winding arms around her waist in turn. Desire strokes a hand through her dark hair and she sighs, content and warm.

She doesn't know how much time has passed, whether she's nodded off or not, before Desire clears her throat, somewhat awkward, and speaks.

"So . . . what'd you think of that?"

Sei stretches, languid, and turns up to look at the anxiously curious look on her sister's face. It's a wonder, she thinks, how pleasant it feels to be simply in her own skin at this moment. For a body that's brought her such pain, that's endured such torment, she truly hadn't thought such a thing would be possible.

She smiles, reaching up to cup Desire's cheek in one hand, stroking her thumb over the flushed skin there.

"I think it was a wonderful idea."


End file.
